Carbon asphyxiation

Olefins, Diolefins, and Acetylenes. Members of this category having up to four carbon atoms are both asphyxiants and anesthetics, and potency for the latter effect increases with carbon chain length. Skin-contact effects are similar to those of paraffins. 

Butylenes are not toxic. The effect of long-term exposure is not known, hence, they should be handled with care. Reference 96 Hsts air and water pollution factors and biological effects. They are volatile and asphyxiants. Care should be taken to avoid spills because they are extremely flammable. Physical handling requires adequate ventilation to prevent high concentrations of butylenes in the air. Explosive limits in air are 1.6 to 9.7% of butylenes. Their flash points range from —80 to —73° C. Their autoignition is around 324 to 465°C (Table 2). Water and carbon dioxide extinguishers can be used in case of fire. 

Products of Combustion Heat, hght, smoke, and asphyxiating and toxic gases are produced by fire. In a hot, well-ventilated fire, combustion is usually nearly complete. Nearly all the carbon is converted to carbon dioxide, all the hydrogen to steam, and oxides of various other elements such as sulfur and nitrogen are produced. 

Inerts Cases Simple asphyxiants Argon methane hydrogen nitrogen helium. Particulates e.g. cement, calcium carbonate. 

Carbon dioxide gas ean aet as an asphyxiant due to displaeement of air, resulting in oxygen defieieney (page 262). Sourees inelude ... 

Asphyxiant Simple asphyxiants are inert gases which deplete the oxygen supply in the breathing air to below the critical value of J8% by volume, such as gaseous fuels or nitrogen. Chemical asphyxiants, such as carbon monoxide and hydrogen cyanide, have a direct biological effect. 

Chemical asphyxiant A substance that interferes with the absorption or utilization of oxygen in the body, e.g., carbon monoxide. 

Carbon dioxide and certain halon compounds have a specialized application for fires in electrical equipment where a non-conducting medium is important. All are toxic to a degree, and operate either by smothering the fire or by a chemical reaction which inhibits combustion. Gas extinguishers must not be used in a confined space because of the toxic risk or the risk of asphyxiation. 

Asphyxiants interfere with the body s oxygen uptake mechanisms. Air normally contains 21% oxygen. Oxygen deficiency in inhaled air, e.g. due to the presence of nitrogen, argon, or carbon dioxide in a confined space, depending on the concentration and duration, may affect the body and ultimately cause death from simple anoxia (Table 4.7). 

Carbon dioxide gas can act as an asphyxiant due. to displacement of air, resulting in oxygen deficiency (page 43). Sources include ... 

The fact that the main direct cause of death in fires has always been the toxicity of combustion products was already discussed in the National Fire Protection Association (NFPA) Quarterly in 1933 [34]. Smoke contains mainly two types of toxic gases asphyxiants and irritants, but the individual toxic gas associated with the largest fire hazard is carbon monoxide (CO). 

Note that C02 acts as neither a simple asphyxiant (like N2) nor a chemical asphyxiant (like CO). The normal concentration of C02 in air is approximately 300 ppm (0.03 vol %). Table 23-19 (Air Products, Carbon Dioxide, Safetygram 18, 1998) illustrates that exposure to air diluted by 5 vol % C02 (yielding an oxygen concentration of 21 x 0.95, or approximately 20 vol %) prompts physiological effects that are more severe than those inferred from Table 23-18 for dilution by the same amount of nitrogen. 

A combination of atoms such as this is called a molecule. A molecule made up of hydrogen and carbon is called a hydrocarbon. This particular compound is a molecule of the asphyxiating gas methane, sometimes called marsh gas or coal miners Black Damp. Instead of writing the compound with the valency bonds showing, it is more commonly written CH4. 

Carbon dioxide gas is an asphyxiant, a potent respiratory stimulant, and both a stimulant and depressant of the central nervous system. Fatalities have occurred after people have entered enclosures where air has been largely displaced by CO2. Therefore, fixed, automatic CO2 systems require a time delay pre-evacuation alarm period (often 30 seconds), warning signs, and an alarm signal incorporated into the system design to allow sufficient time for personnel evacuation prior to CO2 release. Verification of the oxygen level must be made prior to reentry. 

Carbon dioxide (CO2) is a colorless and odorless gas. It is an asphyxiant-causing agent. A concentration of 10% can cause unconsciousness and death from oxygen deficiency. The gas can be released from industrial studies [39], automobile exhaust, environmental tobacco smoke (ETS), and inadequately vented fuel heating systems. It is heavy and accumulates at low levels in depressions and along the floor. 

Toxicology. Carbon dioxide usually is considered a simple asphyxiant, although it also is... 

Asphyxiant A gas or vapor which, when inhaled, may lead to asphyxia. Examples of asphyxiating materials are carbon dioxide and carbon monoxide. 

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